Wallace Loggins will be arraigned Friday on misdemeanor vehicular manslaughter for the Aug. 19 incident, according to Stephanie Ong Stillman, a spokeswoman for San Francisco District Attorney George Gascón.

Police say Dunn, 23, had almost finished crossing Hartford Street on foot when a Muni bus turning left from 18th Street crushed her under its wheels. Dunn had moved to San Francisco from Atlanta a month before she died.

Loggins could face up to a year in county jail. Muni spokesman Paul Rose said the agency is cooperating with the investigation, but offered no further comment.

Filing the charges is a bold move by Gascón, who had warned during a Nov. 29 press conference on pedestrian safety that he might do so. At that event, several pedestrian advocates said they could not remember the last time a Muni driver was charged for hitting someone.

“It’s a big step forward,” Pi Ra, an organizer with Senior Action Network, a coalition of 150 groups representing seniors and people with disabilities, said at the time. “It’s the city prosecuting the city. Usually they want to avoid the conflict and the politics that come with it.”

Gascón charged cyclist Randolph Ang in November with vehicular manslaughter in the death of Dionette Cherney. Police say Ang blew a red light on his bicycle and slammed into Cherney, 68, knocking her to the pavement on July 15. She died Aug. 11 as a result of the injuries.

At the November press conference, Gascón said he was also considering filing charges against an automobile driver who hit and killed a pedestrian and a University of California, San Francisco, shuttle driver for a crash that killed a passenger.

Loggins was driving on a street where Muni buses don't normally travel as he made his way to Market Street to shuttle passengers along the overcrowded F streetcar line. No passengers were on board at the time, and police say that he stopped at a four-way stop sign before making a left turn onto Hartford where Dunn was walking.

After the accident, Muni officials said they would consider requiring buses to follow set routes when going into service.